Retatrutide

What is Retatrutide?

Retatrutide (development code LY3437943) is an investigational injectable peptide from Eli Lilly that activates three metabolic hormone receptors at once: the GIP receptor, the GLP-1 receptor, and the glucagon receptor. It is sometimes called a 'triple-G' or triple-hormone-receptor agonist, a step beyond single-agonist drugs like semaglutide and dual agonists like tirzepatide.

It is important to be clear about its status. As of 2026, retatrutide is not FDA-approved. It is still in phase 3 development and is available only through clinical trials. It is not a compounded, over-the-counter, or research-vial product that a legitimate clinic can dispense, and Strong Health does not provide it.

How Retatrutide works

Each of retatrutide's three targets contributes something different. GLP-1 receptor activation increases satiety, slows gastric emptying, and improves glucose-dependent insulin release. GIP receptor activity also influences insulin secretion and how fat tissue handles nutrients. The novel addition is glucagon receptor agonism, which is thought to increase energy expenditure and reduce liver fat.

The rationale is that combining appetite suppression (GLP-1/GIP) with increased energy expenditure and hepatic fat mobilization (glucagon) could produce greater weight loss than gut-hormone agonism alone. That combination is what the early trials were designed to test.

What Retatrutide is used for

What the evidence shows

In a phase 2, double-blind, randomized, placebo-controlled trial published in the New England Journal of Medicine in 2023, once-weekly retatrutide produced substantial, dose-dependent weight loss — up to roughly 24% of body weight at 48 weeks at the highest dose, among the largest reductions reported for any anti-obesity medication in a trial of this kind [1].

A subsequent systematic review and meta-analysis of randomized data reinforced the weight and metabolic findings while underscoring the dose-dependent gastrointestinal side effects seen across the incretin drug class [2].

These are encouraging but early results. Phase 2 data do not establish long-term safety or the durability of the effect, and large phase 3 outcome trials are what regulators require before approval. We share this context plainly rather than presenting retatrutide as an available treatment.

Dosing & administration context

In trials, retatrutide is given as a once-weekly subcutaneous injection with gradual dose escalation to limit gastrointestinal side effects — the same titration principle used for other incretin therapies. Trial doses are set by study protocols, not by patient self-dosing.

Because retatrutide is investigational, there is no FDA-approved label, no approved dose, and no legitimate compounded or retail source. Any product sold online as 'retatrutide' outside a clinical trial is unverified for identity, purity, and sterility, which is exactly the gray-market risk our clinical model is built to avoid.

Retatrutide is investigational and not FDA-approved. This page is educational, physician-reviewed context — not medical advice, a dosing guide, or an offer to prescribe. Strong Health does not provide retatrutide.

Safety & side effects

The most consistently reported side effects in trials are gastrointestinal — nausea, vomiting, diarrhea, and constipation — and are dose-dependent, tending to ease as the dose is escalated slowly. Increases in heart rate have also been observed, as with other drugs in this space.

Long-term safety is not established. Because retatrutide is still in development, its full risk profile, rare adverse events, and outcomes over years of use remain unknown pending phase 3 results. This uncertainty is a core reason we do not offer it.

Why Strong Health does not offer Retatrutide

Strong Health does not prescribe or provide retatrutide. It is an investigational drug that is not FDA-approved and is available only through clinical trials — not as a compounded or research-grade product. Dispensing an unapproved novel molecule outside a trial would be inconsistent with both the law and our standards.

We document retatrutide because patients ask about it and deserve an honest, physician-reviewed explanation of where the science actually stands. If your goal is medically supervised weight loss today, our physicians evaluate FDA-cleared and appropriately compounded options and build a monitored protocol around your labs — rather than sourcing whatever compound is trending.

Frequently asked questions